Three hundred patients with primary Sjögren's syndrome (pSS) were investigated for liver involvement using clinical, biochemical, immunological and histological data. Seven per cent of patients showed evidence of liver disease either subclinical (2%) or asymptomatic (5%) with elevated liver enzymes. In 6.6% of patients antimitochondrial antibodies (AMA) were detected by immunofluorescence and 27% of pSS patients showed antibodies to pyruvate dehydrogenase (a-PDH) using ELISA. AMA-positive patients were further investigated with transcutaneous liver biopsy. Ninety-two per cent of patients with AMA showed liver involvement with features of chronic cholangitis similar to stage I primary biliary cirrhosis. It is concluded that liver involvement in pSS patients is rare and subclinical with histological features predominantly of stage I primary biliary cirrhosis. AMA is the most sensitive indicator of underlying liver pathology in pSS patients.